[willwashburn]

Down syndrome continues to be the most common chromosomal disorder. Each year, about 6,000 babies are born with Down syndrome, which is about 1 in every 700 babies born.

Between 1979 and 2003, the number of babies born with Down syndrome increased by about 30%.

Older mothers are more likely to have a baby affected by Down syndrome than younger mothers. In other words, the prevalence of Down syndrome increases as the mother’s age increases. Prevalence is an estimate of how often a condition occurs among a certain group of people. To estimate the prevalence of Down syndrome, the number of pregnancies affected by Down syndrome is compared to the total number of live births.